DAKAR, May 25 (Thomson Reuters Foundation) - An Ebola outbreak in the Democratic Republic of Congo could spread to the neighbouring Central African Republic, where militia violence has forced thousands of people to flee across the border, the World Health Organization said on Thursday.

Two cases of the virus have been confirmed by the WHO in Congo's remote northeastern Bas-Uele province since early May. Four people have died so far among the 43 suspected and confirmed cases.

The affected area's isolation - it is about 1,400 kilometres (870 miles) from the capital Kinshasa - has helped contain the spread of the highly contagious hemorrhagic fever, experts say.

Yet recent attacks by Christian militias in Central African Republic's border town of Bangassou have driven about 2,750 people into Bas-Uele, raising the risk that the Ebola outbreak could spread across the border, a WHO representative said.

"There is a big concern about Ebola spreading to Central African Republic after this displacement," said Michel Yao, the WHO's representative in the Central African Republic.

"We are worried as the refugees are close to the epicentre of the outbreak," he told the Thomson Reuters Foundation, adding they could become infected and carry the virus back home.

While this latest Ebola outbreak is Congo's eighth - the most of any country - the Central African Republic lacks experience in dealing with such an epidemic, and its health system is weak after four years of conflict, Yao said.

More than two thirds of its health facilities have been damaged or destroyed by the violence since 2013, when mainly Muslim Seleka rebels seized power, triggering reprisals by Christian "anti-balaka" militias, according to aid agencies.

The Central African Republic set up an Ebola treatment centre and rapid response team following the West Africa epidemic, which killed more than 11,300 people between 2014 and 2016, mostly in Guinea, Sierra Leone and Liberia, the WHO said.

"But there is very limited capacity outside of Bangui (the capital) and it is difficult to travel around the country due to the insecurity," Yao said. "We are concerned about how easily Ebola may spread if it arrives in the Central African Republic."

Health authorities in Congo are monitoring about 365 people who came into contact with sufferers and have dispatched mobile laboratories to the area to speed up testing of people who display symptoms, the WHO said in its latest situation report.

Asked about the potential for using an experimental vaccine, the WHO last week said the logistics were "complex" but that it was working with Congo's government and regulatory authorities.